From BBC

US officials have issued ‘deadly’ cold weather warnings

Parts of the US and Canada are braced for potentially record-breaking low temperatures as a “polar vortex” weather pattern blasts North America.

A winter storm has already blanketed areas of Canada and the north-eastern US with up to 2ft (60 cm) of snow.

More than 3,000 flights were cancelled on Monday, on top of thousands grounded over the weekend.

Schools have been closed in several US states and residents urged to stay indoors for their own safety.

The storm and the deep cold have been blamed for 16 deaths in recent days.

Ice-breakers have been deployed to Lake Michigan as the weather worsens

Temperatures in the north and central US could feel as low as -51C (-60F) with the effect of wind chill, forecasters say.

The plunging temperatures result from the polar vortex, an anti-clockwise pool of cold, dense air.

The vortex has been very strong, with the cold air locked in to Arctic Canada for a long time. Stuck in one place, the air has grown colder and colder.

Cold air is dense, so once released it travels a long way and is thus capable of penetrating so far south, John Hammond from the BBC Weather Centre says.

“The coldest weather in years will be making its presence known from the Upper Midwest to the Mid-Atlantic region for the beginning of the work week,” the US National Weather Service said in a statement.

The states of Ohio, South Dakota and Illinois are among those set to be hit. Tennessee and Kentucky are forecast to see several inches of snow.

It is set to continue to the north-east, where residents are still digging out from the week’s deadly snowstorm.

A man using a snowblower in Lawrence, Kansas, on Sunday In this weather, frostbite can set in on uncovered skin in a matter of moments

A plane is seen after it skidded off a runway after landing at John F Kennedy airport on Sunday A plane skidded off a taxiway at New York’s JFK airport early on Sunday

Green Bay Packers fans deal with frigid temperatures before an NFL football game between the Green Bay Packers and the San Francisco 49ers, 5 January 2014 Green Bay Packers fans make a play on the freezing temperatures before an NFL game in Green Bay, Wisconsin

In eastern Canada, the temperatures are expected to drop quickly throughout Monday. Freezing rain caused long airport delays in Toronto and Ottawa.

Environment Canada’s David Phillips told the BBC the rapid temperature drop expected – about 24 degrees C in 24 hours in cities such as Toronto – means residents could be driving or walking on roads that are “like a rink of ice”.

Cold temperatures could bring lows not seen in 20 years.

Some parts of Canada could see as much as 60cm (23in) of snow over just a few days, Mr Phillips said.

“We have experienced winters like this from time to time, but this one is quite brutal with much snowfall to match the cold,” Bill Brant, who lives in the south-east of the Canadian province of Manitoba, told the BBC in an email.

Heavy snow has also affected US states including New York, Connecticut and Massachusetts. Boston was said to be the worst hit with nearly 18in (45cm) of snow.

For more on this story go to:

http://www.bbc.co.uk/news/world-us-canada-25609411